To convert my toilet to be rainwater fed and not tell the water company

[Lemith]

I'm completing this project at the weekend, making my toilet connected to a reclaimed water tank that is fed by the house run off rainwater. Should easily save the costs of the project in just moved a year (free workmanship).

However I will now be getting free sewerage from this system as they won't charge on the volume. At the same time this water was going into the sewer anyway, but now will be going there less clean.

Is it wrong to do this without telling the water company?

I have no idea but am agog you can run a loo off rainwater.

I wouldn't mention it, you only pay sewerage on clean treated water not water you've harvested.

Chatsworth do similar using their lake water.

I've seen rainwater toilets in IKEA and thought they were a great idea (maybe a bit of a shock for a visitor, or am I the only one who watches the toilet flush?).

I understand that you pay sewerage on incoming water not outgoing, but I expect you use a hosepipe for the garden, so they effectively cancel each other out.

I have a similar system but think I give BACK water in the summer because the airconditioning removes about 10 litres a day which goes down the toilet (too acidic to water the plants).

So, to answer your question, I say don't declare it to the sewerage company.

Is all the rainwater captured for the toilet system or does it still overflow into the sewer when the tank is full?

Could you change it to flow into a soakaway instead?

Have no idea about your question but I think we should all do this. The fact we flush our toilets with drinking quality water is ridiculous. Well done.

I think it's bonkers we flush with 'clean' water anyway.
Well done you.
I didn't realise the sewerage charge was fed by usage, I don't think I'd tell them either as Presumably you've still got usage and so subsequent charges for taps etc.

Water companies assume what you use is what you add to the drains unless you have something like a swimming pool ie filled but not emptied frequently.

I'd love to see more homes doing this too.

I can't see there's an issue either. You pay for your incoming (other) water from the water board; presumably (and I haven't looked at a water bill for ages) there is a percentage of the bill which covers outgoing sewerage; so that fact you're filling you loo cistern with rain water is probably irrelevant. It sounds a good idea.

In theory not all the rainwater will be used by the toilet as if the 500l tank fills up it will go into the drains as it overflows.

Thanks its going to look a bit ugly from the side of the house until I find a way to hide it. But its a real win win project. I'll see how it goes

.... filling your loo ....

My company assumes 95%, in actual fact with this it will be over 100% I'll be sending back. That's where I felt I might be doing wrong. But it seams to pass aibu so I'll keep quiet.

Why on Earth would it be wrong? If the water company are a business and you find a workaround that's legal, then that's just their tough shit!

Go for it OP.

Great idea, it is ridiculous using drinking water to flush toilets. I suppose it's a bit like collecting rain water to water the garden apart from the solids in the system. They do charge for water run off anyway. You could have a load of dogs that you clean up after and flush that in to the system, no one would think of telling the Water Company about that.

Surely that water would otherwise be falling on your roof and flowing away through the drains, so they get it either way. You just use a bit less water.

Unless you use the toilet a huge amount, then it really isn't going to make that much of a difference. If you do use the toilet a huge amount, then I'd tell your doctor first, rather than the water company.

We flush our loo with the bathwater - leave it in from the night before after kids have finished and then bail it in with baby bath throughout the day. Much more cumbersome than yours OP - I am very - well done you!

I wouldn't worry about the water company though - never even thought about it.

OP, what does it say online about all this, I'm sure the water companies have an opinion about this, I've just had a quick look and there seems to be certain regulations about correct fitting etc for safety and all, haven't had a good look though.

There is a page on rainwater harvesting systems on the water company website.

www2.wessexwater.co.uk/saving-water/homeandgarden/default.aspx?id=9056&linkidentifier=id&itemid=9056

However its a bit grey, that looks like for a whole system where you drink it. This is just for one toilet. Obviously its no system meeting x and y regs as its just an old water tank connected with some pipes.

www2.wessexwater.co.uk/saving-water/homeandgarden/default.aspx?id=9056&linkidentifier=id&itemid=9056

if you need to tell the company you've installed the system (they may want to check you've got it right), do it.

Water companies don't measure sewerage in the same way that they measure use if you have a meter; they just assume that roughly what goes in comes out. No need to worry about changes in that, there are plenty of people who will generate less sewerage to compensate for those who produce more. It all balances out.

I looked at rainwater harvesting for the loo...would love to do it but it isn't simply a matter of collecting water in a tank and feeding into your loo! I hope you have looked into it more...
A couple of things - you will have to filter it and treat it.
Filter - Loos (esp modern ones - the ones without a ball cock inside) have a washer (inlet diaphragm) that is quite sensitive to 'bits' - grit collected from your roof or sand or anything. Assuming you are gravity feeding not pumping (as the pump will have a running cost) even taking from not the very bottom of the tank and clearing the bottom out regularly - you do run the risk of getting gunk in your inlet valve, especially when it is actually raining and churning up inside the tank - it won't stop filling so will be constantly overflowing - probably down the loo (internal overflow), could just be a constant trickle - which depending on set up could be mains water once rain tank is empty.
Which is a point - what are you going to do if your rain tank is empty? Have you got a way of diverting back to mains if tank is empty - manual or automatic?
Finally if you have ever had a water butt you'll know this ...but you will have to keep a well sealed lid on it or you will get mosquitos/midges breeding in it. And also you will get algae growth and it will likely go stagnant and absolutely stink...you have to either uv treat or chemically treat every so often.

Oh and do your current gutters drain into the sewage system or into a soak away? You get cheaper sewage rates with a soak away ...and the water companies take that into account when deciding what to charge - there was a big fuss about people with soakaways being overcharged by water companies a few years ago - you could potentially be adding to the overall disposal. (Did wonder about charges for people with water butts for the garden and no soakaway...)

When we moved in (over 10 years ago) I vaguely liked this idea (which is much more helpful to the environment than strapping solar panels on and ripping of pensioners. Back then I learned you needed to tell the water company, as their charges are based on the assumption that water in (i.e. what your meter reads) is the same as water out (i.e. your sewerage). Flushing with rainwater changes this equation (and therefore your bill).

However, the more interesting fact was that the water company technically own the water off the roof (rain). If you aren't passing that back to them, they do need to know.

Again, I give people the fact that all no new builds in the UK are required to have grey-water recycling as standard, as evidence that whatever people are saying about climate change, the reality is they are doing fuck-all. Quite aside from the environmental upsides, such a scheme would - by necessity - have some impact on jobs and growth.

You can get small solar-powered pumps that float on the surface of a butt and lift the water to a header tank.

Unlucky, I will be filtering the water twice and its gravity fed. However yes the diaphragm may get blocked sometimes. The new plastic disks are 20p and I've got lots of them.

I've made a t junction so to switch back to mains water takes two inlet valves to be switched, takes seconds or I'll just use the upstairs loo if it runs dry in the summer. Its unlikely to ever run dry from my calculations.

I've made a t junction so to switch back to mains water takes two inlet valves to be switched

My design would have been a water header tank feeding the toilet(s), connected to mains via a ballcock, and have the rainpump feeding a separate ballcock set slightly higher than the mains one.

Hopefully no intervention required.

Part of the reason the project failed was the only place we could locate a butt happened to miles from the guttering, and a meter lower.

I did think about that design, but would involve much more work. The beauty of my system is its very simple. Its not often your going to be switching from one to another. If it drys up. I'd probably switch back to mains for a few weeks to let it build up. Let's face it in the UK this isn't going to happen often.

Ok - fair enough.
(don't know about plastic discs though? - my diaphragm on a Armitage Shanks is a rubber disk/dome - you can get similar for about £2 in B&Q but they don't fit mine. I need 'special' ones - that only come as part of kit direct from AS for £11 - they sent one FOC in the end otherwise for slightly more hassle I could have replaced the water inlet valve with a good one for £15 that would take the £2 ones in future)
Have you got something to stop water return (from the rainwater pipe) to the mains - say when you turn the rainwater off and mains on - or the danger of you leaving the rainwater on by accident with the mains on - that's the bit they would get stroppiest about -potentially contaminating the mains drinking water....
I agree that we should be doing more rainwater harvesting -or at least grey water recycling - interesting you can't (at least when I looked into it) get any grants/loans etc to do so - from what I read it seems to have a 'proper' system it is less carbon efficient than cleaning the water in a plant... as retrospective installation potentially costs ££££ and you have have no hope of recouping the costs ever - there is no incentive to do it...
I agree new builds should be forced to. Also fit solar pv and solar thermal...
there isn't a true commitment to renewables
Oh and solar pumps are very good but only work when it is light - short days in winter will really effect how they operate!
I do have Solar PV panels - feed in tariff should cover installation cost over 20yrs. I could rant about installation costs being fixed to feed in tariffs - I consider government money not spent wisely - max they can generate at a time is 4kW (although mine are East/West so nearer 2kW) - a fast boil kettle uses 3kW...
With the lower tariffs (I have) you only make money based on electricity savings - which unless you live your life around them -to maximise use when they are generating (so not watching tv with the lights on on a dark winters evening ) it isn't what the sales people predict ...
The same reason why I can't make solar thermal (hot water heating) financially viable. You save about £60- 90 per year on water heating (mains gas). DIY installation (if I could do it) would cost max £1.5k looking to get your money back and start saving after 16+yrs with no maintenance costs. Installer will fit for £5.5k - and as long as they are certified you then can get government money (RHI) for 7yrs which will almost cover the installation cost...I can't help being sceptical about that!